Fluffed polyfill mostly stays where you put it, friction fit. With the bracing we use we are never spanning that far.

People have historical had nails sticking out the internal walls, dowels, strings or a mesh (like Chris suggested). In the last 2 builds we have done that need volume fill (Pensil7 & our variation on the Twin #6 MTM) stayed in place with friction.

Fluffed polyfill mostly stays where you put it, friction fit. With the bracing we use we are never spanning that far.

People have historical had nails sticking out the internal walls, dowels, strings or a mesh (like Chris suggested). In the last 2 builds we have done that need volume fill (Pensil7 & our variation on the Twin #6 MTM) stayed in place with friction.

dave

OTOH, they didn't have a taper that expanded in the direction in which the fill density is reduced, so while the material is certainly light and has a lot of friction, I guess there's always a chance it could slip if a pair of wider boxes are moved around a lot - particularly if MDF is used (please don't - use Chip board instead), or the internal surfaces are treated with a gloss finish.

I'm guessing I'll use some sort of mesh or netting held in place with thumbtacks or something like that...just to keep it in place. Yes, I do move speakers around quite often. I am continuously fascinated by the different sounds/tones/textures that different drivers deliver.